If the OP is picking, then placing, his or her chosen shadow point specifically for the print expected, as any zone system adherent might, then the OP is correctly exposing. That is not to say that that placement choice is even remotely close to the placement choice we might make.
Underexposure only "happens" when shadow detail wanted isn't caught.
Following on that line of thought, adjusting contrast isn't indicated just because a lower exposure level is chosen. Raising film contrast won't necessarily help the OP print the delicate highlights wanted. Measuring or judging SBR is a better way to make that choice.